1. Field of the Invention
The present invention relates to a vehicular illumination lamp that uses a light emitting element as a light source. The present invention specifically relates to a vehicular illumination lamp that is configured so as to radiate light to form a light distribution pattern having a horizontal cut-off line and an oblique cut-off line in an upper end portion thereof.
2. Related Art
In recent years, light emitting elements such as light-emitting diodes have been used as light sources in vehicular illumination lamps.
For example, “Patent Document 1” describes a vehicular illumination lamp that includes: a convex lens positioned on an optical axis extending in the front-back direction of the lamp; and a light emitting element positioned in the proximity of the rear side focal point of the convex lens. A so-called direct projection type of vehicular illumination lamp is configured so as to exercise deflection control, with the use of the convex lens, over the light directly emitted from the light emitting element.
Further, the vehicular illumination lamp described in “Patent Document 1” is configured so that a part of the light directly emitted from the light emitting element is blocked by a shade that is positioned in front of, and in the proximity of, the light emitting element in such a manner that a light distribution pattern having a horizontal cut-off line or an oblique cut-off line in the upper end portion thereof is formed.
[Patent Document 1]    United States Patent Application 2005018443